Heat a large skillet over medium-high heat and brown the beef cubes in batches until all sides are seared. Transfer the beef to the slow cooker.
Add the pearl onions, carrots, potatoes, tomato paste, thyme sprigs, bay leaves, salt, and black pepper to the slow cooker.
Pour in the beef broth and red wine, then stir gently to combine everything.
Cover and cook on low for 7 to 8 hours until the beef is fork-tender and the vegetables are soft.
Remove the thyme sprigs and bay leaves. Stir in the frozen peas and cook for 10 more minutes on low until the peas are heated through.